In this example, we characterize the optical response of a thermally tuned waveguide. The HEAT solver is used to simulate the temperature profile for the waveguide with different input powers. This result is then imported into the Finite-Difference Eigenmode (FDE) solver in MODE to characterize the optical response, including changes to the effective index, phase and loss as a function of the input power.
Thermally Tuned Waveguide Sensor
In this example, we model the thermal tuning of a waveguide sensor. The waveguide sensor used in this example is a functionalized biosensor that senses the change in the effective index of the analyte using a Mach-Zehnder configuration. The same approach can be used to simulate chemical or other types of waveguide sensors. The sensitivity of the sensor is calculated and is thermally tuned using a simple resistive heater.
As photonic integrated circuit designs become increasingly complex, thermal confinement is a factor that limits the number of elements that can be placed on a single chip. This is especially true for silicon photonics since silicon has a very low thermal impedance, and components and circuits must be designed to minimize thermal crosstalk. Numerical simulations are useful for characterizing the effect of thermal cross-talk in photonic integrated circuits. In this example, a methodology is proposed for simulating thermal cross-talk that combines component-level and circuit-level simulations through an optical router with thermo-optically tuned micro-ring resonators.
PIN Mach-Zehnder Modulator
In this example, we will study the performance of a PIN Mach-Zehnder modulator using CHARGE (electrical simulation) and MODE (optical simulation). The modulator is operated in forward bias mode so a significant amount of current will flow through the device, contributing to Joule heating. The heating will increase the temperature of the waveguide and the performance of the modulator will be degraded.
Photothermal Heating in Plasmonic Nanostructures
In this example, we investigate the effect of photothermal heating in plasmonic nanostructures. Using Lumerical's DGTD solver for optical simulation and the HEAT solver for thermal simulation, we look at two types of plasmonic antennas (dipole and diabolo) under varying optical intensity and compare their performance.
In this example, we calculate the temperature changes in a metamaterial microbolometer sensor caused by infrared light absorption.